Changeset 278659 in webkit

Timestamp:

Jun 9, 2021, 7:47:55 AM (4 years ago)

Author:

Alan Bujtas

Message:

[Flexbox] FlexItem stays invisible after initial layout
​https://bugs.webkit.org/show_bug.cgi?id=226778

Reviewed by Simon Fraser.

Source/WebCore:

RenderFlexibleBox::layoutAndPlaceChildren() initiates repaint() on newly constructed flex items by checking their everHadLayout bit.
This is similar to what we do for regular block layout when block level boxes appear.
However flexitems are laid out multiple times, first right after they are constructed in constructFlexItem. This initial layout
sets everHadLayout bit to true which makes the check in layoutAndPlaceChildren somewhat late.

Test: fast/flexbox/repaint-issue-when-flex-item-appears.html

• rendering/FlexibleBoxAlgorithm.cpp:

(WebCore::FlexItem::FlexItem):

• rendering/FlexibleBoxAlgorithm.h:
• rendering/RenderFlexibleBox.cpp:

(WebCore::RenderFlexibleBox::constructFlexItem):
(WebCore::RenderFlexibleBox::layoutAndPlaceChildren):

LayoutTests:

• fast/flexbox/repaint-issue-when-flex-item-appears-expected.txt: Added.
• fast/flexbox/repaint-issue-when-flex-item-appears.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/flexbox/repaint-issue-when-flex-item-appears-expected.txt (added)
• LayoutTests/fast/flexbox/repaint-issue-when-flex-item-appears.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/FlexibleBoxAlgorithm.cpp (modified) (2 diffs)
• Source/WebCore/rendering/FlexibleBoxAlgorithm.h (modified) (2 diffs)
• Source/WebCore/rendering/RenderFlexibleBox.cpp (modified) (4 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2021-06-09  Alan Bujtas  <zalan@apple.com>
+
+        [Flexbox] FlexItem stays invisible after initial layout
+        https://bugs.webkit.org/show_bug.cgi?id=226778
+
+        Reviewed by Simon Fraser.
+
+        * fast/flexbox/repaint-issue-when-flex-item-appears-expected.txt: Added.
+        * fast/flexbox/repaint-issue-when-flex-item-appears.html: Added.
+
 2021-06-09  Diego Pino Garcia  <dpino@igalia.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-06-09  Alan Bujtas  <zalan@apple.com>
+
+        [Flexbox] FlexItem stays invisible after initial layout
+        https://bugs.webkit.org/show_bug.cgi?id=226778
+
+        Reviewed by Simon Fraser.
+
+        RenderFlexibleBox::layoutAndPlaceChildren() initiates repaint() on newly constructed flex items by checking their everHadLayout bit.
+        This is similar to what we do for regular block layout when block level boxes appear.
+        However flexitems are laid out multiple times, first right after they are constructed in constructFlexItem. This initial layout
+        sets everHadLayout bit to true which makes the check in layoutAndPlaceChildren somewhat late.
+
+        Test: fast/flexbox/repaint-issue-when-flex-item-appears.html
+
+        * rendering/FlexibleBoxAlgorithm.cpp:
+        (WebCore::FlexItem::FlexItem):
+        * rendering/FlexibleBoxAlgorithm.h:
+        * rendering/RenderFlexibleBox.cpp:
+        (WebCore::RenderFlexibleBox::constructFlexItem):
+        (WebCore::RenderFlexibleBox::layoutAndPlaceChildren):
+
 2021-06-09  Alexander Mikhaylenko  <alexm@gnome.org>
 

trunk/Source/WebCore/rendering/FlexibleBoxAlgorithm.cpp

@@ -36 +36 @@
 namespace WebCore {
 
-FlexItem::FlexItem(RenderBox& box, LayoutUnit flexBaseContentSize, LayoutUnit hypotheticalMainContentSize, LayoutUnit mainAxisBorderAndPadding, LayoutUnit mainAxisMargin)
+FlexItem::FlexItem(RenderBox& box, LayoutUnit flexBaseContentSize, LayoutUnit hypotheticalMainContentSize, LayoutUnit mainAxisBorderAndPadding, LayoutUnit mainAxisMargin, bool everHadLayout)
     : box(box)
     , flexBaseContentSize(flexBaseContentSize)
@@ -42 +42 @@
     , mainAxisBorderAndPadding(mainAxisBorderAndPadding)
     , mainAxisMargin(mainAxisMargin)
-    , frozen(false)
+    , everHadLayout(everHadLayout)
 {
     ASSERT(!box.isOutOfFlowPositioned());

trunk/Source/WebCore/rendering/FlexibleBoxAlgorithm.h

@@ -42 +42 @@
 class FlexItem {
 public:
-    FlexItem(RenderBox&, LayoutUnit flexBaseContentSize, LayoutUnit hypotheticalMainContentSize, LayoutUnit mainAxisBorderAndPadding, LayoutUnit mainAxisMargin);
+    FlexItem(RenderBox&, LayoutUnit flexBaseContentSize, LayoutUnit hypotheticalMainContentSize, LayoutUnit mainAxisBorderAndPadding, LayoutUnit mainAxisMargin, bool everHadLayout);
 
     LayoutUnit hypotheticalMainAxisMarginBoxSize() const
@@ -65 +65 @@
     const LayoutUnit mainAxisMargin;
     LayoutUnit flexedContentSize;
-    bool frozen;
+    bool frozen { false };
+    bool everHadLayout { false };
 };
 

trunk/Source/WebCore/rendering/RenderFlexibleBox.cpp

@@ -1309 +1309 @@
 FlexItem RenderFlexibleBox::constructFlexItem(RenderBox& child, bool relayoutChildren)
 {
+    auto childHadLayout = child.everHadLayout();
     child.clearOverridingContentSize();
     if (childHasIntrinsicMainAxisSize(child)) {
@@ -1336 +1337 @@
     LayoutUnit childMinMaxAppliedMainAxisExtent = adjustChildSizeForMinAndMax(child, childInnerFlexBaseSize);
     LayoutUnit margin = isHorizontalFlow() ? child.horizontalMarginExtent() : child.verticalMarginExtent();
-    return FlexItem(child, childInnerFlexBaseSize, childMinMaxAppliedMainAxisExtent, borderAndPadding, margin);
+    return FlexItem(child, childInnerFlexBaseSize, childMinMaxAppliedMainAxisExtent, borderAndPadding, margin, childHadLayout);
 }
     
@@ -1738 +1739 @@
         const auto& flexItem = children[i];
         auto& child = flexItem.box;
-        bool childHadLayout = child.everHadLayout();
 
         ASSERT(!flexItem.box.isOutOfFlowPositioned());
@@ -1769 +1769 @@
             m_relaidOutChildren.add(&child);
         child.layoutIfNeeded();
-        if (!childHadLayout && child.checkForRepaintDuringLayout()) {
+        if (!flexItem.everHadLayout && child.checkForRepaintDuringLayout()) {
             child.repaint();
             child.repaintOverhangingFloats(true);